Thaw fish, if frozen; cut into 1/2-inch pieces. Set aside. In a medium mixing bowl combine egg product, bread crumbs, onion, mayonnaise, mustard, parsley, lime peel, and salt. Add fish; mix well. Form mixture into twelve 1/2-inch-thick patties, about 2 1/2 inches in diameter.
Coat patties with cornmeal. In a large nonstick skillet or on griddle, heat oil. Add half of the fish cakes. Cook over medium heat for 2 to 3 minutes per side or until fish just flakes when tested with a fork and patties are gold. Repeat with the remaining cakes. For each serving, place three fish cakes on a plate along with 2 tablespoons Green Goddess Sauce.
In a blender container or food-processor bowl combine yogurt, sour cream, and tarragon. Cover and process or blend until smooth. Transfer to bowl. Stir in sour cream, chives, lime juice, and garlic. Serve with fish cakes. Cover and refrigerate remaining sauce to use over salad greens. Makes 3/4 cup.